Methods and structures for reducing lateral diffusion through cooperative barrier layers

ABSTRACT

A covered substrate is described, which comprises: (a) a flexible substrate layer; and (b) a plurality of cooperative barrier layers disposed on the substrate layer. The plurality of cooperative barrier layers further comprise one or more planarizing layers and one or more high-density layers. Moreover, at least one high-density layer is disposed over at least one planarizing layer in a manner such that the at least one high-density layer extends to the substrate layer and cooperates with the substrate layer to completely surround the at least one planarizing layer. When combined with an additional barrier region, such covered substrates are effective for enclosing organic optoelectronic devices, such organic light emitting diodes, organic electrochromic displays, organic photovoltaic devices and organic thin film transistors. Preferred organic optoelectronic devices are organic light emitting diodes.

FIELD OF THE INVENTION

[0001] The present invention relates to structures that protect organicoptoelectronic devices from the surrounding environment.

BACKGROUND OF THE INVENTION

[0002] Organic optoelectronic devices, including circuits, such asorganic light emitting diodes, organic electrochromic displays, organicphotovoltaic devices and organic thin film transistors, are known in theart and are becoming increasingly important from an economic standpoint.

[0003] As a specific example, organic light emitting devices (“OLEDs”),including both polymer and small-molecule OLEDs, are potentialcandidates for a great variety of virtual- and direct-view typedisplays, such as lap-top computers, televisions, digital watches,telephones, pagers, cellular telephones, calculators and the like.Unlike inorganic semiconductor light emitting devices, organic lightemitting devices are generally simple and relatively easy andinexpensive to fabricate. Also, OLEDs readily lend themselves toapplications requiring a wide variety of colors and to applications thatconcern large-area devices. In general, two-dimensional OLED arrays forimaging applications are known in the art and are typically composed ofa plurality of OLEDs (one or more of which forms a pixel) arranged inrows and columns. Each individual OLED in the array is typicallyconstructed with a first transparent anode (such as ITO), an organicelectroluminescent layer on the first electrode, and a metallic cathodeon the organic electroluminescent medium. Other OLED architectures arealso known in the art such as transparent OLEDs (transparent cathodecontact), and inverted OLEDs. Substrate materials may include glass,plastic, metal foil, silicon wafers, etc.

[0004] In forming an OLED, a layer of metal is typically utilized as thecathode to ensure efficient electron injection and low operatingvoltages. However, metals and their interface with the organic materialare susceptible to oxygen and moisture, which can severely limit thelifetime of the devices. Moreover, moisture and oxygen are also known toincrease “dark spot areas” in connection with OLEDs. Components ofvarious other organic optoelectronic devices (e.g., organicelectrochromic displays, organic photovoltaic devices and organic thinfilm transistors) are likewise susceptible to attack from exteriorenvironmental species, including water and oxygen.

SUMMARY OF THE INVENTION

[0005] The above and other challenges are addressed by the presentinvention.

[0006] According to a first embodiment of the invention, a coveredsubstrate is provided, which comprises: (a) a flexible substrate layer;and (b) a plurality of cooperative barrier layers disposed on thesubstrate layer. The plurality of cooperative barrier layers in thisembodiment further comprise one or more planarizing layers and one ormore high-density layers. Moreover, at least one high-density layer isdisposed over at least one planarizing layer in a manner such that theat least one high-density layer extends to the substrate layer andcooperates with the substrate layer to completely surround the at leastone planarizing layer.

[0007] According to a second embodiment of the invention an organicoptoelectronic device structure is provided, which comprises: (a) afirst barrier region comprising a flexible substrate layer and aplurality of cooperative barrier layers disposed on the substrate layer;(b) an organic optoelectronic device disposed over the first barrierregion, the organic optoelectronic device selected from an organic lightemitting diode, an organic electrochromic display, an organicphotovoltaic device and an organic thin film transistor; and (c) asecond barrier region disposed over the organic optoelectronic device.As in the prior embodiment, the plurality of cooperative barrier layersfurther comprises one or more planarizing layers and one or morehigh-density layers. Moreover, at least one high-density layer isdisposed over at least one planarizing layer in a manner such that theat least one high-density layer extends to the substrate layer andcooperates with the substrate layer to completely surround the at leastone planarizing layer. Preferred organic optoelectronic devices areorganic light emitting diodes.

[0008] For each of these embodiments, each overlying first cooperativebarrier layer that is disposed over one or more underlying firstcooperative barrier layers preferably extends to the substrate layer ina manner such that the one or more underlying first cooperative barrierlayers are surrounded by the substrate layer and the overlying firstcooperative barrier layer.

[0009] Preferably, the first cooperative barrier layers comprise analternating series of two or more first planarizing layers and two ormore first high-density layers, and more preferably comprise analternating series of 3 to 7 first planarizing layers and 3 to 7 firsthigh-density layers.

[0010] The second barrier region in the second embodiment above can,like the first barrier region, comprise a plurality of secondcooperative barrier layers, which further comprise one or more secondplanarizing layers and one or more second high-density layers. At leastone second high-density layer is preferably disposed over at least onesecond planarizing layer in a manner such that the at least one secondhigh-density layer extends to the first barrier region and cooperateswith the first barrier region to completely surround the at least onesecond planarizing layer. The second cooperative barrier layers can bearranged in essentially the same fashion as the first barrier layers.

[0011] One advantage of the present invention is that organicoptoelectronic structures are produced that provide an effective barrierbetween the organic optoelectronic device and the ambient atmosphere,reducing adverse effects due to chemical species in the ambientatmosphere, such as moisture and oxygen.

[0012] Another advantage of the present invention is that organicoptoelectronic structures are provided that address problems associatedwith lateral diffusion of moisture and oxygen within their barrierlayers.

[0013] These and other embodiments and advantages of the presentinvention will become readily apparent to those of ordinary skill in theart upon review of the disclosure to follow.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1a is a cross-sectional view of a covered substrate.

[0015]FIG. 1b is a cross-sectional view of an OLED structure, whichutilizes the covered substrate of FIG. 1a.

[0016]FIG. 2 is a cross-sectional view of a covered substrate inaccordance with an embodiment of the present invention.

[0017]FIG. 3 is a cross-sectional view of an OLED structure, whichutilizes the covered substrate of FIG. 2, in accordance with anembodiment of the present invention.

[0018]FIGS. 4a-4 g are cross-sectional views illustrating a process forforming the covered substrate of FIG. 2 and the OLED structure of FIG.3, in accordance with an embodiment of the present invention.

[0019]FIG. 5 is a cross-sectional view of a covered substrate, inaccordance with an embodiment of the present invention.

[0020]FIG. 6 is a cross-sectional view of an OLED structure, whichutilizes the covered substrate of FIG. 2, in accordance with anembodiment of the present invention.

[0021]FIG. 7 is a cross-sectional view of an OLED structure, inaccordance with an embodiment of the present invention.

[0022]FIG. 8 is a schematic diagram of an apparatus for forming thecovered substrate of FIG. 2, in accordance with an embodiment of theinvention.

[0023]FIG. 9 is a schematic diagram of another apparatus for forming thecovered substrate of FIG. 2, in accordance with an embodiment of theinvention.

[0024]FIG. 10 is a cross-sectional view of an OLED structure, whichutilizes a covered substrate in accordance with an embodiment of thepresent invention.

[0025] As is commonly the case with such figures, the above aresimplified schematic representations and the actual structures willdiffer in numerous respects including the relative scale of thecomponents.

DETAILED DESCRIPTION

[0026] The present invention now will be described more fullyhereinafter with reference to the accompanying drawings in whichpreferred embodiments of the invention are shown. This invention may,however, be embodied in different forms and should not be construed aslimited to the embodiments set forth herein.

[0027] As used herein, a “layer” of a given material includes a regionof that material whose thickness is small compared to both its lengthand width. Examples of layers include sheets, foils, films, laminations,coatings, and so forth. As used herein a layer need not be planar, butcan be bent, folded or otherwise contoured, for example, to at leastpartially envelop another component.

[0028] Referring now to FIG. 2, a covered substrate 100 is shown inaccordance with an embodiment of the invention. The covered substrate100 includes a substrate layer 110 and a barrier region 120 (which iscomposed of multiple cooperative barrier layers as discussed below)disposed on the substrate layer 110.

[0029] The substrate layer 110 can be a rigid or flexible layer. It ispreferably a flexible layer and is typically selected based on one ormore characteristics, such as flexibility and conformability to othersurfaces, dimensional stability during processing (e.g., where web-basedprocessing is contemplated), adequate bonding with other components suchas the cooperative barrier layers of the barrier region 120, and opticalcharacteristics.

[0030] Preferred flexible substrate layers contain paper, fabric, metalfoil, flexible glass layers (available, for example, from Schott GlassTechnologies), and/or polymer layers.

[0031] More preferred flexible layers are layers that comprise one ormore of the polymer components, including polyesters, polycarbonates,polyethers, polyimides, polyolefins, and fluorocarbons that are capableof providing a strong adhesive bond with other materials. Suchcomponents can be found, for example, in homopolymers, copolymers andpolymer blends. Examples of some preferred polymer components include,for example, polyethersulphones, polyarylates, polyestercarbonates,polyethylenenaphthalates, polyethyleneterephthalates, polyetherimides,polyacrylates, Kapton® polyimide film available from DuPont, Appear® PNB(polynorbornene) available from BF Goodrich, Aclar® fluoropolymeravailable from Honeywell, and Arton® available from BF Goodrich.

[0032] The substrate layer 110 typically ranges from 75 to 625 micronsin thickness.

[0033] As with the substrate layer 110, the barrier region 120 is alsotypically selected based on one or more the above characteristics.Moreover, in its role as a barrier, the barrier region 120 also acts toblock the transport of oxygen, water and any other detrimental moleculesfrom the outside environment.

[0034] Preferred barrier regions 120 for the practice of the presentinvention are cooperative barrier layers that include both layers ofplanarizing material 121 a-c and layers of high-density material 122a-c. These cooperative barrier layers are preferably provided in analternating configuration. Preferably, 1 to 10 pairs of these layers,more preferably 3 to 7 pairs, are used. Although three alternating pairsare illustrated in FIG. 2, other layer arrangements are possible.Moreover, while it is preferred for the bottom layer to be a layer ofplanarizing material 121 a as shown in FIG. 2, the bottom layer can alsobe, for example, a layer of high-density material. Also, while thestructure in FIG. 2 is shown as terminating in a high-density layer 122c, the top layer can be, for example, a planarizing layer.

[0035] By “planarizing material” is meant a material that forms a smoothplanar surface upon application, rather than forming a surface thatreflects irregular contours of the underlying surface. A preferredmaterial is one that, when deposited onto a surface, forms anon-conformal liquid. This could be, for example, a polyacrylate monomer(this material is then subjected to ultraviolet light, crosslinking themonomer to form a polyacrylate). Preferred planarizing materials arepolymers, such as fluorinated polymers, parylenes, cyclotenes andpolyacrylates. Layers of such planarizing materials 121 a-c can beprovided using techniques known in the art, for example, by dipping,spin coating, sputtering, evaporative coating, spraying, flashevaporation, chemical vapor deposition and so forth.

[0036] By “high-density material” is meant a material with sufficientlyclose atomic spacing such that diffusion of outside species,particularly water and oxygen, are hindered. Preferred high-densitymaterials include inorganic materials such as silicon oxides (SiOx),including silicon monoxide (SiO) and silicon dioxide (SiO₂), siliconnitrides (typically Si₃N₄), silicon oxynitrides, aluminum oxides(typically Al₂O₃), indium-tin oxides (ITO) and zinc indium tin oxides.Metals are also effective, particularly where transparency is notrequired. Layers of high-density material 122 a-c can be applied usingtechniques known in the art such as thermal evaporation, sputtering,plasma-enhanced chemical vapor deposition (PECVD) methods andelectron-beam techniques.

[0037] Examples of multilayer barrier regions comprising layers of bothhigh-density material and layers of planarizing material are disclosed,for example, in U.S. Pat. No. 5,757,126, the entire disclosure of whichis hereby incorporated by reference.

[0038] Continuous processing techniques, such as web-based processingtechniques, typically involve the formation of large sheets of material.Such large sheets can be subsequently subdivided into sheet sizesappropriate for the final application (e.g., into sheets the size of acomputer monitor screen). In the case of a barrier region containingcooperative barrier layers on a substrate, cutting a large sheetproduces a structure with exposed edges like that shown in FIG. 1a.Unfortunately, in exposing the edges of layers 121 a-c and 122 a-c inthe barrier region 120, lateral diffusion of moisture and oxygen, aswell as other species, becomes increasingly problematic.

[0039] This difficulty can be better seen with reference to FIG. 1b,which illustrates an OLED 140 disposed on the barrier region 120. Anadditional barrier region 150 (a metal can is shown) is secured to thestructure by adhesive region 130, to protect the OLED 140 from thesurrounding environment.

[0040] From this structure, it can be seen that the ends of each of thelayers 121 a-c and 122 a-c are exposed to exterior moisture in oxygen.The diffusivity of water and oxygen in the planarizing layers 1221 a-cis significantly greater than the diffusivity of these species in thehigh-density layers 122 a-c. Hence, layers 121 a-c each presents a pathof relatively low resistance to moisture and oxygen.

[0041] This situation is improved by the structures of the presentinvention. For example, reference is now made to FIG. 3 in which an OLED140, an additional barrier region 150 and an adhesive region 130 areprovided in connection with the covered substrate 100 of FIG. 2, formingan OLED structure 190. In contrast to FIG. 1b, however, each planarizinglayer 121 a-c is separated from the outside environment by at least onehigh-density layer 122 a-c. As a result, lateral diffusion of water andoxygen within the planarizing layers 121 a-c is reduced relative to FIG.1b.

[0042] Although the cooperative barrier layers 121 b-c and 122 a-c inthis embodiment each completely covers an underlying cooperative barrierlayer (i.e., by covering the top of the underlying layer and extendingdown the sides of the underlying layer to the substrate), benefits canbe achieved by completely covering underlying layers with only a singlelayer, for example, a high-density layer 122 c, as shown in FIG. 10.

[0043] Referring again to FIG. 3, adhesive region 130 is disposedbetween the high-density layer 122 c and the additional barrier region150, bonding the additional barrier region 150 to the layer 122 c. Theadhesive region 130 is selected to provide a good bond between the layer122 c and the additional barrier region 150 and to provide a barrier tomoisture and oxygen, without damaging the OLED during curing (e.g., dueto off-gassing). Preferred materials for these purposes includeultraviolet-curable and thermally curable epoxy materials. Preferredepoxy materials are ultraviolet curable, single-part epoxies such asEpotek OG159. The thickness of the adhesive region typically ranges from25 to 100 microns.

[0044] Although not necessarily immediately apparent from thetwo-dimensional rendering of FIG. 3, the adhesive region 130 typicallyencircles the OLED 140, having an appearance somewhat like that of agasket occupying the space between layer 122 c and the additionalbarrier region 150. As a result, in the embodiment shown, adhesiveregion 130 cooperates with the layer 122 c and the additional barrierregion 150 to isolate the OLED from the outside environment.

[0045] In some embodiments of the invention, a gettering material (notshown) is placed adjacent the OLED 140, such that the gettering material(along with the OLED) is surrounded by the layer 122 c, additionalbarrier region 150 and adhesive region 130. The gettering material actsto capture any moisture, oxygen, etc. that may reach the interior of thedevice 190 and harm the OLED 140. Preferred gettering materials includeCaO and BaO. One particularly preferred product is HICAP2000, a CaOpaste obtainable from Cookson SPM.

[0046] The OLED structure can be any OLED known in the art. For example,as noted above, the OLED will generally comprise an anode layer(typically transparent), a cathode layer, and a light-emitting layer(emission layer) disposed between the anode and cathode layer. The lightemitting layer can be provided in connection with a number ofconfigurations, including the following: (a) a three-layer configurationcomprising a hole transporting layer, an emission layer and an electrontransporting layer (i.e., a double heterostructure configuration), (b) atwo-layer configuration comprising a hole transporting layer and a layerthat provides both emission and electron transporting functions or atwo-layer configuration comprising an electron transporting layer and alayer that provides both emission and hole transporting functions (i.e.,single heterostructure configurations) and (c) a configurationcomprising a single layer that provides hole transporting, electrontransporting and emission functions (i.e., a single layerconfiguration). In each configuration, additional layers may also bepresent, for example, layers that enhance hole injection or electroninjection, or layers that serve to block holes or electrons. Severalstructures for such devices are discussed, for example, in U.S. Pat. No.5,707,745, the entire disclosure of which is hereby incorporated byreference. Other more complex OLED architectures are also practiced inthe art.

[0047] Although an OLED 140 is shown in connection with the variousfigures, other organic optoelectronic devices, such as organicelectrochromic displays, organic photovoltaic devices and organic thinfilm transistors, can be used in place of the OLED 140 that is shown.

[0048] Depending on the application, the additional barrier region 150opposite the OLED 140 from layer 122 c may or may not be required to beoptically transparent. Typical materials for the additional barrierregion 150 include polymers, ceramics and metals.

[0049] Metals are frequently preferred due to their excellent barrierproperties, and can be provided in a number of configurations such as inthe form of a metal can and or metal foil, with metal foils beingpreferred due to ease of manufacture. Preferred metal foils includealuminum, gold and indium, as well as other foils known in the art. Theadditional barrier region 150 may or may not contact the OLED 140.

[0050] Like metals, ceramics also offer low permeability and providetransparency in many cases. Preferred ceramics are glasses, morepreferably soda lime and borosilicate glasses.

[0051] Polymers are often preferred where optical transparency isdesired or where ease of continuous manufacture (e.g., web-basedmanufacture) is desired. Preferred polymers include polyesters,polyethersulphones, polyimides and fluorocarbons.

[0052] Polymers can also be provided as planarizing layers in connectionwith a series of cooperative barrier layers, such as those discussedabove in connection with the barrier layer 120. An embodiment of such asstructure is shown in FIG. 6, which illustrates an additional barrierregion 150 consisting of an alternating series of planarizing layers 151a-c and high-density layers 152 a-c. In this embodiment, no adhesiveregion 130 is used, since sufficient bonding strength between thesuccessive layers exists.

[0053] In some instances, however, the substrate layer 110 can becomesaturated with water. One consequence of this situation is that layer122 c as illustrated in FIG. 6 can also become saturated with water overtime. Because layer 122 c is in direct contact with the OLED 140, thisis particularly problematic. One way of addressing this challenge is toprovide an additional barrier region 160 between the layer 122 c and theOLED 140 as shown in FIG. 7. As with barrier region 120, barrier region160 is preferably composed of multiple cooperative barrier layers. Forexample, layers of planarizing material 161 a-c and layers ofhigh-density material 162 a-c can be provided as shown.

[0054] The formation of planarizing and high-density layers over asubstrate material will now be discussed in connection with FIGS. 4a-4g, FIG. 8 and FIG. 9. Referring now to FIG. 4a, a first planarizingmaterial layer 121 a is first deposited on a substrate 110. (Aspreviously noted, a high-density layer can be deposited first, ratherthan a planarizing layer). Subsequently, as shown in FIG. 4b, a firsthigh-density material layer 122 a is deposited over the firstplanarizing material layer 121 a. The area covered by the firsthigh-density material layer 122 a is sufficiently larger than the areaof the first planarizing material layer 121 a, such that the firsthigh-density material layer 122 a completely covers the firstplanarizing material layer 121 a and extends to the substrate 110 on allsides. In this way the first high-density material layer 122 a and thesubstrate 110 together act to completely enclose the first planarizingmaterial layer 121 a.

[0055] Subsequently, in a similar fashion, a second planarizing materiallayer 121 b is deposited over the first high-density material layer 122a (see FIG. 4c), followed by the deposition of a second high-densitymaterial layer 122 b (FIG. 4d), a third planarizing material layer 121 c(FIG. 4e), and a third high-density material layer 122 c (FIG. 4f).

[0056] After deposition of the desired number of planarizing andhigh-density layers (three pairs are shown), an OLED 140 is thenprovided on the now-covered substrate using known techniques as shown inFIG. 4g. An additional barrier region 150 is then adhered to thesubstrate via adhesive region 130 in this embodiment, completelyenclosing the OLED 140 within the OLED structure 190, protecting it frommoisture and oxygen.

[0057] Deposition of progressively larger cooperative barrier layers canbe achieved in a number of ways. Preferred techniques are continuoustechniques such as web-based processing techniques. An apparatus 200containing various rolls (only rolls 290 are shown) for materialmovement, material cooling and so forth, as well as other componentssuch as ultraviolet curing lights, is illustrated in FIG. 8. Using thisapparatus 200, a web of substrate 210 is passed under several depositionsources 221 a-c and 222 a-c within a web-coating apparatus. In thisembodiment, sources 221 a-c are used for the deposition of materials forplanarizing layers, while sources 222 a-c are used for the deposition ofmaterials for high-density layers. Preferred sources are thermalevaporation, sputtering, PECVD and electron beam sources for thehigh-density layers, and thermal evaporation, organic vapor phasedeposition (OVPD), chemical vapor deposition (CVD), spraying and flashevaporation sources for the planarization layers.

[0058] An arrow indicates the direction of substrate 210 movement withinapparatus 200. Deposition source 221 a, is first used to deposit firstplanarizing material layer 121 a. Then, deposition source 222 a is usedto deposit first high-density material layer 122 a, deposition source221 b is used to deposit second planarizing material layer 121 b,deposition source 222 b is used to deposit second high-density materiallayer 122 b, deposition source 221 c is used to deposit thirdplanarizing material layer 121 c, and deposition source 222 c is used todeposit third high-density material layer 122 c.

[0059] In FIG. 8, each deposition source is provided with an aperturethat is larger than that of the adjacent upstream source (i.e., thesource to the left), such that the material being deposited from eachsource progressively covers a wider area as the substrate proceedsdownstream (i.e., from left to right).

[0060] Other embodiments are clearly possible. For example, as shown inFIG. 9, each deposition source can have the same aperture. However, inthis embodiment, each source 221 b-c and 222 a-c is provided at a largerdistance from the substrate than is the adjacent upstream source (i.e.,the source to the left), such that the material being deposited fromeach source again covers a progressively wider area as the substrateproceeds downstream (i.e., from left to right).

[0061] Coverage of a given cooperative barrier layer can extend beyondthe minimum amount needed to cover the top and sides of the underlyinglayer. For instance, as shown in FIG. 5, layers 122 a, 121 b, 122 b caneach spread out over the substrate 110 surface by a certain amount.

[0062] Although the present invention has been described with respect toseveral exemplary embodiments, there are many other variations of theabove-described embodiments that will be apparent to those of ordinaryskill in the art. It is understood that these variations are within theteachings of the present invention, and that the invention is to belimited only by the claims appended hereto.

1. An organic optoelectronic device structure comprising: a first barrier region comprising a substrate layer and a plurality of cooperative barrier layers disposed on said substrate layer, said plurality of cooperative barrier layers further comprising one or more planarizing layers and one or more high-density layers, wherein at least one high-density layer is disposed over at least one planarizing layer in a manner such that said at least one high-density layer extends to said substrate layer and cooperates with said substrate layer to completely surround said at least one planarizing layer; an organic optoelectronic device disposed over said first barrier region, said organic optoelectronic device selected from an organic light emitting diode, an organic electrochromic display, an organic photovoltaic device and an organic thin film transistor; and a second barrier region disposed over said organic optoelectronic device.
 2. The organic optoelectronic device structure of claim 1, wherein each overlying cooperative barrier layer that is disposed on one or more underlying cooperative barrier layers extends to the substrate layer in a manner such that said one or more underlying cooperative barrier layers are surrounded by said substrate and each said overlying cooperative barrier layer.
 3. The organic optoelectronic device structure of claim 1, wherein said cooperative barrier layers comprise an alternating series of two or more planarizing layers and two or more high-density layers.
 4. The organic optoelectronic device structure of claim 1, wherein said second barrier region comprises a metal layer.
 5. The organic optoelectronic device structure of claim 1, wherein said substrate layer is a polymer substrate layer.
 6. The organic optoelectronic device structure of claim 5, wherein said polymer substrate layer comprises one or more polymer components selected from a polyester, a polyolefin, a polycarbonate, a polyether, a polyimide and a polyfluorocarbon.
 7. The organic optoelectronic device structure of claim 1, wherein said one or more planarizing layers comprise a material selected from fluorinated polymers, parylenes, cyclotenes and polyacrylates.
 8. The organic optoelectronic device structure of claim 1, wherein said one or more high-density layers comprise a material selected from metal oxides, metal nitrides, metal carbides, metals and metal oxynitrides.
 9. An OLED structure comprising: a first barrier region comprising a substrate layer and a plurality of first cooperative barrier layers disposed on said substrate layer, said plurality of first cooperative barrier layers further comprising one or more first planarizing layers and one or more first high-density layers, wherein at least one first high-density layer is disposed over at least one first planarizing layer in a manner such that said at least one first high-density layer extends to said substrate layer and cooperates with said substrate layer to completely surround said at least one first planarizing layer; an OLED disposed over said first barrier region, said OLED comprising an anode, a cathode and an organic emissive layer; and a second barrier region disposed over said OLED.
 10. The OLED structure of claim 9, wherein each overlying first cooperative barrier layer that is disposed over one or more underlying first cooperative barrier layers extends to the substrate layer in a manner such that said one or more underlying first cooperative barrier layers are surrounded by said substrate layer and said overlying first cooperative barrier layer.
 11. The OLED structure of claim 9, wherein said first cooperative barrier layers comprise an alternating series of two or more first planarizing layers and two or more first high-density layers.
 12. The OLED structure of claim 11, wherein said alternating series comprises 3 to 7 first planarizing layers and 3 to 7 first high-density layers.
 13. The OLED structure of claim 9, wherein said one or more first planarizing layers comprise a material selected from fluorinated polymers, parylenes, cyclotenes and polyacrylates.
 14. The OLED structure of claim 9, wherein said one or more first high-density layers comprise a material selected from metal oxides, metal nitrides, metal carbides, metals and metal oxynitrides.
 15. The OLED structure of claim 9, wherein said one or more first high-density layers comprises a material selected from silicon oxide, silicon nitride, aluminum oxide, indium tin oxide and zinc indium tin oxide.
 16. The OLED structure of claim 9, wherein said substrate layer is a polymer substrate layer.
 17. The OLED structure of claim 17, wherein said polymer substrate layer comprises one or more polymer components selected from a polyester, a polyolefin, a polycarbonate, a polyether, a polyimide and a polyfluorocarbon.
 18. The OLED structure of claim 17, wherein said polymer substrate layer comprises one or more polymer components selected from a polyethersulphone, a polyarylate, a polyestercarbonate, a polyethylenenaphthalate, a polyethyleneterephthalate, a polyetherimide, a polyacrylate, and a polynorbornene.
 19. The OLED structure of claim 18, wherein said polymer substrate layer is a polyethyleneterephthalate layer.
 20. The OLED structure of claim 17, wherein said polymer substrate layer ranges from 75 to 625 microns in thickness.
 21. The OLED structure of claim 9, wherein said second barrier region comprises a metal layer.
 22. The OLED structure of claim 9, wherein said first barrier region is bonded to said second barrier region by an adhesive region.
 23. The OLED structure of claim 22, wherein said adhesive region comprises an epoxy material.
 24. The OLED structure of claim 9, wherein said second barrier region comprises a plurality of second cooperative barrier layers, said plurality of second cooperative barrier layers further comprising one or more second planarizing layers and one or more second high-density layers, and wherein at least one second high-density layer is disposed over at least one second planarizing layer in a manner such that said at least one second high-density layer extends to said first barrier region and cooperates with said first barrier region to completely surround said at least one second planarizing layer.
 25. The OLED structure of claim 24, wherein each overlying second cooperative barrier layer that is disposed over one or more underlying second cooperative barrier layers extends to the first barrier region in a manner such that said one or more underlying second cooperative barrier layers are surrounded by said first barrier region and said overlying second cooperative barrier layer.
 26. The OLED structure of claim 24, wherein said second cooperative barrier layers comprise an alternating series of two or more second planarizing layers and two or more second high-density layers.
 27. The OLED structure of claim 26, wherein said alternating series comprises 3 to 7 second planarizing layers and 3 to 7 second high-density layers.
 28. The OLED structure of claim 24, wherein said one or more second planarizing layers comprise a material selected from fluorinated polymers, parylenes, cyclotenes and polyacrylates.
 29. The OLED structure of claim 24, wherein said one or more second high-density layers comprise a material selected from metal oxides, metal nitrides, metal carbides, metals and metal oxynitrides.
 30. The OLED structure of claim 24, wherein said one or more second high-density layers comprises a material selected from silicon oxide, silicon nitride, aluminum oxide, indium tin oxide and zinc indium tin oxide.
 31. The OLED structure of claim 9, further comprising a gettering material disposed between said first and second barrier regions.
 32. The OLED structure of claim 9, further comprising a third barrier region disposed between said first barrier region and said OLED, said third barrier region comprising a plurality of third cooperative barrier layers, said plurality of third cooperative barrier layers further comprising one or more third planarizing layers and one or more third high-density layers, wherein at least one third high-density layer is disposed over at least one third planarizing layer in a manner such that said at least one third high-density layer extends to said first barrier region and cooperates with said first barrier region to completely surround said at least one third planarizing layer.
 33. A covered substrate comprising: a flexible substrate layer; and a plurality of cooperative barrier layers disposed on said substrate layer, said plurality of cooperative barrier layers further comprising one or more planarizing layers and one or more high-density layers, wherein at least one high-density layer is disposed over at least one planarizing layer in a manner such that said at least one high-density layer extends to said substrate layer and cooperates with said substrate layer to completely surround said at least one planarizing layer.
 34. The covered substrate of claim 33, wherein each overlying cooperative barrier layer that is disposed over one or more underlying cooperative barrier layers extends to the substrate layer in a manner such that said one or more underlying cooperative barrier layers are surrounded by said substrate layer and said overlying cooperative barrier layer.
 35. The covered substrate of claim 33, wherein said cooperative barrier layers comprise an alternating series of two or more planarizing layers and two or more high-density layers.
 36. The covered substrate of claim 35, wherein said alternating series comprises 3 to 7 planarizing layers and 3 to 7 high-density layers.
 37. The covered substrate of claim 33, wherein said one or more planarizing layers comprise a material selected from fluorinated polymers, parylenes, cyclotenes and polyacrylates.
 38. The covered substrate of claim 33, wherein said one or more high-density layers comprise a material selected from metal oxides, metal nitrides, metal carbides, metals and metal oxynitrides.
 39. The covered substrate of claim 33, wherein said one or more high-density layers comprises a material selected from silicon oxide, silicon nitride, aluminum oxide, indium tin oxide and zinc indium tin oxide.
 40. The covered substrate of claim 33, wherein said substrate layer is a polymer substrate layer.
 41. The covered substrate of claim 40, wherein said polymer substrate layer comprises one or more polymer components s elected from a polyester, a polyolefin, a polycarbonate, a polyether, a polyimide and a polyfluorocarbon.
 42. The covered substrate of claim 40, wherein said polymer substrate layer comprises one or more polymer components selected from a polyethersulphone, a polyarylate, a polyestercarbonate, a polyethylenenaphthalate, a polyethyleneterephthalate, a polyetherimide, a polyacrylate, and a polynorbornene.
 43. The covered substrate of claim 40, wherein said polymer substrate layer ranges from 75 to 625 microns in thickness. 